Adjustable chair-back



H. SHAW. ADJUSTABLE CHAIR BACK.

Patented Nov. 2, 1920.

2 SHEETS SHEET 120671 01 54 A) W W, I

H. SHAW. A DJUST ABLE CHAIR BACK.

APPLICATION mm JULY 12. I920.

1,357,826. Patented Nov; 2, 1920,.

2 SHEETS-SHEET 2- UNITED STATES ARRY SHAW, OF CHICAGO, ILLIivoIs.

ADJUSTABLE CHAIR-BACK.

Specification of Letters Patent.

4 PatentedNov. 2, 1920.

Application filed July 12, 1920. Serial No. 395,625.

To all whom it may concern Be it known that I, HARRY SHAW citizen of the United States, residing at Illinois, have invented certain new and useful Improvements in Adjustable lhair- Backs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to chairs or stools, and in its general aspects aims to provide a chair back which will automatically adjust itself in angularity about a horizontal axis so as to adapt itself to the comfort of the user of the chair, and which can readily be adjusted both as to its height above the seat and as to its horizontal distance with respect to the seat. More particularly, my in vention aims to provide a swiveling support for a chair back so arranged that it can readily be adjusted as to its height without using tools, and desirably to provide a support of this kind in which the riser portion connecting the back proper with the seat of the chair or stool can be made from a single piece of wire. Furthermore, my invention aims to provide simple and effective means for connecting such a riser to the seat of the chair and for permitting an adjustment of the riser backward or forward with respect to the said seat. Still further objects will appear from the following specification and from the accompanying drawings, in which Figure 1 is a side elevation of a chair back embodying my invention and of a part of the seat of a stool to which it is attached.

Fig. 2 is an enlarged and fragmentary rear view of the same parts.

Fig. 3 is an enlarged vertical section taken through the chair back along the correspondingly'numbered line of Fig. 2.

Fig. 4 is a fragmentary bottom view of the seat and of the parts secured to the same.

In accomplishing the objects of my invention after the manner of the accompanying drawings, I fasten to the seat of the chair or stool a riser which includes an upper horizontal portion adapted to act as a shaft upon which the back proper can be swiveled. This riser is desirably made of a steel rod or heavy wire bent into the form of an inverted U and having a straight dhicago,

bight connecting the two shanks, which bight acts as the swiveling shaft. The shanks of the U are desirably curved sub stantially as shown in Fig. 1 and have their free ends secured in any suitable manner to the seat of the chair or stool. as for example, according to the manner hereafter described. I then mount upon the rear of the back proper a suitable swivel member engaging the said horizontal bight or shaft portion of the riser, so that the back is swiveled on this horizontal portion and can swing freely about the latter when adjusting itself to the user of the chair or stool. The swivel member provided for this purpose preferably has a plurality of bearing portions adapted interchangeably to afford the swiveling, so that the engagement can be shifted from one to another of these bearing portions for the purpose of adjusting the effective height ofthe swivel back to diflerent users of the chair or stool.

To accomplish this latter purpose, I am here showing a metal plate 1 as fastened to the wooden back 2 of the chair by means of screws 3, which screws also serve for fastening a hinge plate 4 upon the outer face of the said fixed plate adjacent to its upper end. Hinged to this hinge plate 4 at its own upper end is a swiveling plate 5 which has a plurality of grooves 6 directed toward the front of the chair (or toward the fixed plate 1), each of these grooves being of such a diameter and depth that it can freely lower end of the fixed plate 1 and is normally held in a position close to the latter by a latch 8 pivoted on a screw 9 which is driven into the chair back 2. Thus arranged, it will be obvious from Figs. 1 and. 2 that the back 2 will be swivele d upon the horizontal. bight portion 7 of the riser, so that this back can tilt freely about the said horizontal portion as an axis. By rotating the latch 8 a quarter turn about the screw 9, which is easily done by means of a handle 10 on the latch, the swiveling plate can be released from its normal position and swung back as shown in Fig. 3, thereby permitting the bight or shaft portion 7 on the riser to be moved from one to another of the said grooves, after which the swiveling plate can again be clamped in its normal position.

- The user ofsuch a chair or stool can there- .bar 13.

fore instantly adjust the height of the chair back to his or her comfortwithout using tools.

To secure the shanks 11 of the riser to the seat 12 ofthe chair or'stool, I desirably fastento the underside of this seat an angle bar 13 extending transversely of the riser and having a vertical web equipped with a pair of apertures through which the free end portions 17 of the riser slidably extend. These end portions desirably are straight and have their tips disposed between the bottom of the seat 12 and a pair of cleats 14 by means or which cleats the riser ends are clamped against the bottom of the seat to prevent them from sliding backward or forward through the apertures in the angle However, by slightly loosening the screws 16 which fasten these cleats in their clamping'position, i can slide the riser either forward or backward with respect to the seat of the chair orstool, thereby permitting a corresponding 1 adjustment of the chair back. By spacing the apertures in the vertical web of the angle bar somewhat from the lower surface of the horizontal web of this angle bar, I cause the end portions 17 of the riser to extend at an angle to the bot tom of the seat against which they are clamped, thereby obtaininga cramping action which insures a rigid clamping of the riser to the seat and prevents a rearward pressure on the back of the chair from'sliding the riser out of the position for which items adjusted;

In practice, the metal plates 1 and 5 are desirably made of a width closely approximating the distancebetween the shanks 11 of theriser, thereby preventing the swivelingrmeans and the back proper from sliding sideways upon the bight 7 of the riser. I also desirably provide the swiveling groove formations entirely within the swiveling plate soas to permit the use ofaplain surface on the fixed plate 1,th ereby reducing thecost of the latter andavoiding the necessity of indenting the wooden back of the chair. However I do not wish to be limited to theseor vother details of the construction and arrangement here disclosed, as it will be obvious that numerous additions, omissions or other ch'anges'might be made without departing from the spirit of a my invention or from the appended claims.

I claimi as my invention:

1. In an adjustable chair, a seat, a riser V securedto the seat, a back, and swiveling means connecting the back with the riser with freedom for movement about a horizontal axis, the said means being arranged for swiveling the back at any one of a plurality of heights with respect to the riser.

2! In an adjustable chair, a riser secured to the seat thereof and having a horizontal upper portion, a chair back, and means se 7 horizontal bight, a chair back: and a pair' of swivel elements carried by the back and cooperating to afford a bearingin which the said horizontal bight is ournaled.

4. In an adjustable chair, a riser secured to the seat thereof and comprising a pair of shanks connected at their upper ends by a horizontal bight, a chair back and a pair of swivel elements carried by the back and cooperating to afford aplurality of vertically spaced bearings in any one' of which the said horizontal bight may interchangeably be journaled.

A chair as per claim t, in which one of the swivel elements is fast on the chair back and in which the said two elements are relatively movable, in combination with means for normally latching the said elements in a position in which they cooperate in affording the said bearings.

6. Means for swiveling a chair back on the horizontal portion of a riser carried by the seat of the chair, comprising a fixed plate secured to the rear of the said'back, a swiveling plate hinged to the fixed plate and having a plurality of horizontal grooves adapted interchangeably to house the said horizontal portion of the riser, and means for latching the swiveling plate close to the fixed plate to confine the horizontal portion of the riser in one of the said grooves.

Signed at Chicago, Illinois, July'3rd, 1920 HARRY SHAW. 

